1. Field of the Invention
The present invention generally relates to timebase difference correcting apparatus and, more particularly, to a timebase corrector for a video signal which is suitably applied to a high definition video apparatus such as a high definition television receiver and the like.
2. Description of the Prior Art
As a transmitting system for transmitting a high vision or high definition video signal, a so-called three-transmission line system composed of Y signal, P.sub.B signal, P.sub.R signal or G signal, B signal and R signal is known, and in a video tape recorder (VTR), for example, to which these video signals are transmitted, a delay of time (difference of delay) occurs among respective signals due to time delay elements such as transmission cable, filter, amplifier and so on.
Such difference of delay causes the quality of a reproduced image to be considerably deteriorated when the video signal is dubbed in the compatible reproduction and dubbing mode, and therefore, it is necessary to absorb the difference of delay of the respective signals on a magnetic tape.
Conventionally, such difference of delay is absorbed by the accuracy of digital clock, analog filter, delay line or the like.
However, according to the conventional method, the accuracy of absorbing difference of delay is not sufficient and the difference of delay is absorbed before the video signal is input to the video tape recorder. As a consequence, difference of delay produced in the recording system of the video tape recorder is not absorbed and causes the quality of the reproduced picture to be considerably deteriorated when the video signal is dubbed in the compatible reproduction and dubbing mode.